Dry vegetation is often difficult to compost as the microbes need moisture to multiply. Where water is scarce it cannot be used to add to compost heaps. By using the digestate from the Flexigester on such waste vegetation not only can the nutrients from the digestate be captured but also the vegetation broken down to be added to soil as an organic rich compost.

Compost ventures in Sub-Saharan Africa and other similar tropical countries suffer from two extremes of weather. When it is hot and dry any moisture in the vegetation quickly evaporates leaving the compost heap too dry to breakdown. However in the rainy season the vegetation becomes too wet and waterlogged preventing aerobic breakdown.

The SOWTech Wrap-over Composting System aims to protect the composting material from these extremes and provide a constant environment conducive to composting. The vegetation is placed in breathable bags wrapped in a breathable sheet. Digestate from the Flexigester is added to the bags via Dribble Tube. This percolates through the vegetation. Moisture is evaporated by the sun, condenses on the sheet and is returned to the vegetation. In the rainy season the wrap-over sheet protects the contents from the rain and prevents it becoming waterlogged.

Once the vegetation has broken down it is removed and used on land and any run off water is collected for use as a liquid fertiliser. Heat is given off by the composting reaction and this can further aid pathogen kill.